Left Behind
by hmweasley
Summary: While working on his summer schoolwork, Regulus hears noises in the hallway. He's surprised to find his brother and his boyfriend removing Sirius' things from his bedroom. He's even more surprised to hear that Sirius won't be coming back.


**Content notice: This story contains references to homophobia.**

* * *

Regulus was knee-deep in his summer Charms homework when he heard noises in the hallway outside his room. There was a small crash as something hit the floor and then frantic whispering. Neither of the voices belonged to his parents, but one of them was certainly his brother.

Tossing down his quill, Regulus went to see what was going on. He wasn't surprised when he found Sirius and Remus Lupin outside Sirius' room even though Lupin had never been welcomed into their house by their parents. That was one rule that Sirius was actually breaking for the first time, and it was a dangerous one.

"What are you doing?" Regulus asked, keeping his voice low.

He may not have approved of Sirius' choices in who to date, but he didn't welcome their mother screaming over it any more than Sirius did. He looked down at the mess they'd created in the hall. Sirius' trunk was half open, and the crash he'd heard had been a third of its contents spilling onto the floor.

"None of your business," Sirius muttered before directing his wand at his things and making them fly back into the trunk.

Regulus cringed at Sirius' messy spellwork. It wasn't that difficult to neatly organize everything with the right focus, but Sirius wasn't interested in putting in that much effort. His things arranged themselves into a chaotic mess that would take ages to sort through later.

"Where are you going?" Regulus asked, looking Lupin up and down in suspicion.

"James' house," Sirius replied without looking up from his trunk.

"Did Mother and Father give you permission?"

They never let Sirius go to Potter's house, and if they had finally cracked, there would have been screaming first about Sirius' choice of friends. Screaming which Regulus should have heard, unless it had happened while he was out visiting a friend of his own.

Sirius snorted.

"Of course not. I'm not asking them for permission to do anything."

Regulus raised one eyebrow.

"You're in for hell when you get back then."

Sirius still didn't look at him as he said, "I'm not coming back."

Ice ran through Regulus' veins as he narrowed his eyes.

"What are you on about, Sirius? Why do you have to talk such nonsense?"

"It's not nonsense, dear brother," Sirius said with a roll of his eyes. "I hate this goddamn family and everything it stands for. I hate being yelled at all the time just because I decided to wear a bit of red. This family is shit, and I'm done."

He snapped the lock on his trunk shut.

"Besides," he continued, finally making eye contact with Regulus, "you should be thankful. Once I'm gone, they won't spend their time yelling at me. That means more time spent fawning over you."

Regulus couldn't come up with a response before Sirius had fled back into his room to retrieve more of his things. Instead of his brother, he was left facing Lupin, who was inspecting the wallpaper as if it were a work of art.

"Is he going to be with you?" Regulus asked, struggling to keep most of his hatred for the other boy out of his voice.

His question startled Lupin, who frowned at Regulus and fiddled with the sleeve of his robes as he answered.

"No, he'll be at James' house like he said. The Potters have more room than my family, and things are...happier there."

Regulus knew nothing about Potter Manor, but he didn't doubt they'd have more room than a common half-blood. Despite being denied a place in the Sacred Twenty-Eight, the Potter family went back far enough to have a house as large as Grimmauld Place.

"Can you—" Regulus cut himself off, glancing at Sirius' door. He couldn't believe how vulnerable he was about to be with a half-blooded Gryffindor. "Can you make sure he's all right?"

Lupin didn't answer at first. His eyes had narrowed, and Regulus saw the distrust in his eyes. Regulus shifted his gaze to the floor, wishing it would swallow him up. He should never have opened his mouth. He should have stayed in his room and let Sirius flee without interruption.

"Of course I will," Lupin replied. "I always do."

Regulus gave a short nod, still looking at the floor, before Sirius came back into the hallway with a rucksack slung over his shoulder. Regulus didn't look up as Sirius pushed past him, motioning for Lupin to follow.

With the hall quiet once again, Regulus chanced a look into Sirius' bedroom. Pictures still adorned the walls. He could have fooled himself that Sirius hadn't left for good.

* * *

As they walked away from Grimmauld Place, heading for the Leaky Cauldron where James could meet them, Remus couldn't help but glance back at the house as it was swallowed up by those on either side. Seeing Regulus in his family home had been different from seeing him at school surrounded by other Slytherins.

"Do you think he would've come with us if you'd offered?" Remus asked Sirius, resisting another look over his shoulder. "He seemed upset that you were leaving."

Sirius snorted and waved his hand impatiently through the air.

"No," he said. "There's no way Regulus would do anything against our dear parents' wishes. He's a lost cause, Moony. I've accepted it."

Thought Sirius smiled at him, Remus saw the sadness in his eyes. There was always an extra layer of bitterness when Sirius talked about his brother compared to the rest of his family. While he was always up for insulting his mother or father, he avoided mentioning Regulus when possible.

"Moony," Sirius said gently, pulling Remus out of his thoughts.

Coming to a stop, he looped an arm around Remus' waist and tugged him closer.

"Don't tell me you feel sorry for Regulus," Sirius said. "He's made his decision. Don't forget the shit he said when he heard we were dating."

There had been one comment directed at them in the hallway that had stung. Remus couldn't deny that, and Sirius had been troubled by the way his brother had laughed along with his friends. Still, the two brothers had shared the same loaded look they always did when they saw each other, and Remus was sure that Regulus' actions had been motivated more by a desire to fit in than real hatred of his own.

It didn't excuse him, but it did make Remus wonder if there was hope—

Sirius sighed and leaned forward to kiss Remus on the lips, giving him a sad smile as he pulled away.

"Your loving nature is endearing, Remus, but you've got to stop thinking of ways to save my brother. The ship has sailed."

Remus nodded, doing his best to push the sad look on Regulus' face from his thoughts. Sirius was right that there was nothing he could do about it, but he wished there was just to lessen Sirius' frown when he thought of the other boy.

He gripped his boyfriend's hand in his as they walked down the streets of London, arguing as they went over what to get Peter for his birthday, all discussion of Regulus safely avoided.

* * *

 **Prompts:**

 **Hogwarts Challenges and Assignments**

Seasonal Challenge - Air Element: Gemini - (pairing) Remus/Sirius

Seasonal Challenge - Audrey's Dessert Challenge: chocolate - Remus Lupin

Word count: 1,197


End file.
